Centrifugal clutches transmit the torque from an input drive shaft of a motor to an output driven member only when the input drive shaft has reached a predetermined speed. The carrier is fixedly connected to the input shaft so as to rotate therewith. Centrifugal weights are supported on the carrier so as to be slideable in the radial direction and rotatable therewith. On the other hand, the clutch drum is fixedly connected with the output driven member so as to rotate therewith. The clutch drum is rotatable relative to the input shaft and the carrier with its centrifugal weights when the clutch is not engaged. As soon as the input shaft with its carrier has reached a predetermined speed, the centrifugal force will move the centrifugal weights outwardly in the radial direction until they frictionally engage and entrain the clutch drum thereby causing it and the connected output driven member to follow their rotational movement. The centrifugal clutch is provided with axial securing means to ensure an exact alignment of the centrifugal weights relative to the clutch drum as is required for a reliable force transmission.
In a known centrifugal clutch of the aforementioned type, both axial securing means are in the form of retaining discs or washers. The discs are provided on respective sides of the carrier and secure the centrifugal weights against axial displacement on the carrier. The discs are connected to the carrier so that they rotate therewith and are of complex construction since they have to secure all centrifugal weights against axial displacement. The retaining discs extend from an area close to the axis of the centrifugal clutch radially outwardly over and beyond the radius of the centrifugal clutch. The retaining discs have to be relatively thick to be able to take up the forces exerted thereon at a relatively large movement arm without becoming deformed which, however, makes the discs relatively large and heavy. Since the discs provide axial support for all centrifugal weights simultaneously, a relatively large axial clearance may occur with relatively low manufacturing tolerances of the centrifugal weights and/or the discs, allowing movement of the centrifugal weights relative to the discs during operation. The result is deformation and wear of the discs which may adversely affect the accurate axial alignment of the centrifugal weights.